JP2001223153A - Resist peeling apparatus and resist peeling liquid management method, and semiconductor device and method of manufacturing the same semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the element ratio of a resist peeling liquid to the adequate range for a long period of time in the resist for peeling resist residues adhered to a semiconductor wafer using a resist peeling liquid consisting of multiple elements. SOLUTION: A peeling liquid tank 14 is provided to store the resist peeling liquid. A conductivity monitor 46 is provided to monitor the conductivity of the resist peeling liquid. An additional element tank 50 is also provided to estimate the element ratio of the resist peeling liquid based on such conductivity, and adds the adequate amount of resist peeling liquid based on the estimation result to cover the shortage of such resist peeling liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist stripping apparatus and a resist stripping liquid management method, and more particularly to a resist stripping apparatus used for stripping a resist residue on a semiconductor wafer and a method of adjusting the state of the resist stripping liquid. The present invention relates to a management device for managing information.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit manufacturing process, after dry etching for forming wirings and holes, etc.
A process for removing a resist residue remaining on the semiconductor wafer, that is, a resist stripping process is performed.
The resist stripping process is performed, for example, by cleaning the semiconductor wafer with a resist stripper containing an organic amine or the like.

[0003]

The component ratio of the resist stripping solution changes over time. Particularly, an amine-based stripping solution, which is generally used as a resist stripping solution, is used in a high-temperature environment, and therefore its component ratio changes drastically. If such a change occurs, the wiring on the wafer or the like is excessively etched by the resist stripping solution, or the inability to remove the residue of the resist stripping solution is reduced.

For this reason, in the process of manufacturing a semiconductor integrated circuit, a method of regularly exchanging a resist stripping solution is usually used. Such replacement of the resist stripping solution causes an increase in the production cost of the semiconductor integrated circuit. Therefore, in order to reduce the cost of the semiconductor integrated circuit, it is essential to reduce the cost of the resist stripper, more specifically, to extend the life of the resist stripper.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a resist stripping apparatus capable of extending the life of a resist stripping solution by maintaining the component ratio of the resist stripping solution within an appropriate range. The primary purpose is to provide. It is a second object of the present invention to provide a method for managing a resist stripping solution for maintaining the component ratio of the resist stripping solution within an appropriate range and extending its life.

[0006]

According to the first aspect of the present invention,
A resist stripping apparatus for stripping a resist residue adhered to a semiconductor wafer by using a resist stripping solution composed of multiple components, a stripping solution tank storing the resist stripping solution, and a conductivity of the resist stripping solution. A conductivity monitor for monitoring, based on the conductivity, means for estimating the component ratio of the resist stripping solution, and based on the estimation result of the component ratio, an insufficient amount of the resist stripping solution, an appropriate amount of the resist And a component addition mechanism for adding to the stripping solution.

According to a second aspect of the present invention, there is provided the resist removing apparatus according to the first aspect, wherein the component adding mechanism includes a mechanism for adding water as the insufficient component. .

[0008] The invention described in claim 3 is claim 1 or 2.
The resist stripping apparatus according to any one of claims 1 to 3, further comprising a buffer tank that heats the added component, between the component adding mechanism and the stripping solution tank.

According to a fourth aspect of the present invention, there is provided the resist removing apparatus according to any one of the first to third aspects, wherein the component adding mechanism includes a continuous replenishing mechanism for continuously adding the insufficient component; An intermittent replenishment mechanism for intermittently adding a new solution of the resist stripping solution or the insufficient component so as to compensate for the carry-out of the chemical solution from the stripping solution tank by the semiconductor wafer. It is.

According to a fifth aspect of the present invention, in the resist stripping apparatus according to the fourth aspect, the intermittent replenishment mechanism performs intermittent addition immediately after the semiconductor wafer is unloaded from the stripping solution tank. It is characterized by performing.

According to a sixth aspect of the present invention, there is provided the resist stripping apparatus according to any one of the first to fifth aspects, wherein the resist stripping liquid is withdrawn from the stripping liquid tank and the resist stripping liquid is stripped. Equipped with a circulation path to circulate through the liquid tank,
The conductivity monitor monitors the conductivity of the resist stripping solution flowing through the circulation path, and the component addition mechanism detects the shortage in the circulation path at a position downstream of the position where the conductivity monitor monitors the conductivity. It is characterized by adding components.

According to a seventh aspect of the present invention, there is provided the resist stripping apparatus according to any one of the first to sixth aspects, further comprising an exhaust mechanism for sucking and exhausting an atmosphere around the stripping liquid tank,
The exhaust mechanism adjusts an exhaust capability based on the electric conductivity.

The invention according to claim 8 is the resist stripping apparatus according to any one of claims 1 to 7, further comprising means for analyzing the component ratio of the resist stripping solution using an absorbance meter, The component addition mechanism is based on both the component ratio estimated based on the electrical conductivity and the component ratio analyzed using the absorbance meter, and based on both the insufficient components of the resist stripping solution and an appropriate amount of the resist stripping solution. It is characterized by being added to a liquid.

According to a ninth aspect of the present invention, there is provided the resist stripping apparatus according to any one of the first to eighth aspects, wherein the monitoring data representing the component ratio of the resist stripping solution is a data item for which the component ratio is controlled to a predetermined value. When indicating that it is out of the range, or when the monitoring data shows a rapid change exceeding a predetermined speed, a means for inhibiting the loading of a new semiconductor wafer into the stripper bath is provided. Is what you do.

The invention according to claim 10 is the invention according to claims 1 to 9
The resist stripping apparatus according to any one of the above, wherein the monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined management range,
Alternatively, when the monitoring data shows a sudden change exceeding a predetermined speed, a means for immediately carrying out the semiconductor wafer in the stripping solution tank from the stripping solution tank and transporting the semiconductor wafer to a normal post-process is provided. It is assumed that.

[0016] The invention according to claim 11 is the invention according to claims 1 to 9
The resist stripping apparatus according to any one of the above, wherein the monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined management range,
Or, when the monitoring data shows a sudden change exceeding a predetermined speed, the resist stripping solution in the stripping solution tank is immediately discharged, and further, a new solution of the resist stripping solution near room temperature is added to the stripping solution tank. Is provided.

According to a twelfth aspect of the present invention, there is provided a method for managing a resist stripping solution composed of multiple components for stripping a resist residue adhering to a semiconductor wafer, the method comprising the steps of: Monitoring the conductivity of the solution; estimating a component ratio of the resist stripping solution based on the conductivity; and, based on the estimation result of the component ratio, determining an insufficient component of the resist stripping solution. Adding to the resist stripping solution.

According to a thirteenth aspect of the present invention, in the resist stripping liquid management method according to the twelfth aspect, the step of adding the insufficient component includes a step of adding water as the insufficient component. Is what you do.

The invention according to claim 14 is the resist stripping liquid management method according to claim 12 or 13, wherein the insufficient component is heated to a predetermined temperature before the insufficient component is supplied to the stripping solution tank. The method further comprises the step of:

According to a fifteenth aspect of the present invention, in the resist stripping liquid management method according to any one of the twelfth to fourteenth aspects, the step of adding a deficient component includes continuously adding the deficient component. A sub-step and a sub-step of intermittently adding a new solution of the resist stripping solution or the insufficient component so as to compensate for the carry-out of the chemical solution from the stripping solution tank by the semiconductor wafer. It is assumed that.

According to a sixteenth aspect of the present invention, in the resist stripping solution management method according to the fifteenth aspect, the sub-step of intermittently adding the insufficient component includes unloading the semiconductor wafer from the stripping solution tank. It is executed immediately after being executed.

According to a seventeenth aspect of the present invention, there is provided the resist stripping liquid management method according to any one of the twelfth to sixteenth aspects, wherein the monitoring of the conductivity has flowed out of the stripping liquid tank into a circulation path. The resist stripper is performed on the resist stripper, and the deficient component is added downstream of the position where the conductivity is monitored in the circulation path, and then the stripper tank together with the resist stripper flowing through the circulation path. It is characterized by flowing into.

The invention according to claim 18 is the resist stripping liquid management method according to any one of claims 12 to 17, wherein the capability of the exhaust mechanism for sucking and exhausting the atmosphere around the stripping liquid tank is provided. The method further comprises the step of adjusting based on the conductivity.

According to a nineteenth aspect of the present invention, there is provided the resist stripping liquid management method according to any one of the twelfth to eighteenth aspects, wherein the step of analyzing the component ratio of the resist stripping liquid using an absorbance meter is performed. The method further comprises the step of adding the missing component, the component ratio estimated based on the electrical conductivity, based on both the component ratio analyzed using the absorbance meter, the missing component of the resist stripping solution. Is added to the resist stripping solution in an appropriate amount.

According to a twentieth aspect of the present invention, there is provided the resist stripping liquid management method according to any one of the twelfth to nineteenth aspects, wherein the monitoring data representing the component ratio of the resist stripping solution indicates that the component ratio is a predetermined value Detecting that the monitoring data is out of the control range, or that the monitoring data shows a sudden change exceeding a predetermined speed, and when any of the above two situations is detected, Prohibiting the loading of a new semiconductor wafer.

According to a twenty-first aspect of the present invention, there is provided the resist stripping liquid management method according to any one of the twelfth to twentieth aspects, wherein the monitoring data representing the component ratio of the resist stripping solution is such that the component ratio is a predetermined value. Detecting that the monitoring data is out of the management range, or detecting that the monitoring data shows a rapid change exceeding a predetermined speed;
When any one of the three conditions is detected, immediately carrying out the semiconductor wafer in the stripping solution tank from the stripping solution tank and transporting the semiconductor wafer to a normal post-process. It is.

According to a twenty-second aspect of the present invention, there is provided the resist stripping liquid management method according to any one of the twelfth to twentieth aspects, wherein the monitoring data representing the component ratio of the resist stripping solution is such that the component ratio is a predetermined value. Detecting that the monitoring data is out of the management range, or detecting that the monitoring data shows a rapid change exceeding a predetermined speed;
When any one of the two situations is detected, immediately discharging the resist stripping solution in the stripping solution tank, further, supplying a new solution of a resist stripping solution near room temperature to the stripping solution tank, Is further included.

According to a twenty-third aspect of the present invention, there is provided a semiconductor device, wherein the semiconductor device is manufactured by using the resist stripping apparatus according to any one of the first to eleventh aspects.

According to a twenty-third aspect of the present invention, there is provided a method for manufacturing a semiconductor device, wherein a resist on a semiconductor wafer is treated with a resist stripping liquid managed by the resist stripping liquid management method according to any one of claims 12 to 22. The method includes a step of removing a residue.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals, and redundant description will be omitted.

Embodiment 1 FIG. 1 is a diagram illustrating an overall configuration of a resist stripping apparatus according to Embodiment 1 of the present invention. The resist stripping apparatus 10 includes a plurality of tanks including a stripping liquid tank 14 in a space surrounded by the outer wall 12. Stripper bath 14
A loader 20 for transferring the semiconductor wafer 16 to the transfer arm 18 is arranged at the front stage. A second stage, which is a rinsing solution tank or a washing tank, is provided downstream of the stripping solution tank 14.
The tank 22 and the dryer 24 are arranged side by side. An unloader 26 for receiving the semiconductor wafer from the transfer arm 18 is disposed further downstream of the dryer 24.

The semiconductor wafer 16 carried into the resist stripper 10 is transferred from the loader 20 to the transfer arm 18 in lot units. The transfer arm 18 sequentially transfers the semiconductor wafer 16 into the stripper tank 14, the second tank 22, or the dryer 24 while moving inside the resist stripper 10, and then transfers the semiconductor wafer 16 to the unloader 26. Each of the tanks including the stripper tank 14 is provided with a lid 28 that is opened only when the semiconductor wafer 16 is loaded and unloaded. For this reason, the predetermined processing in each tank can be performed in a closed space.

The resist stripping apparatus 10 has an exhaust port 30 for exhausting the air inside the apparatus to the outside. The exhaust port 30 is provided along the longitudinal direction of the resist stripping device 10, and can suck air in the device from a wide area. A controllable exhaust pressure is led to the exhaust port 30. By controlling the exhaust pressure of the resist stripping device 10, it is possible to adjust the exhaust capability based on the exhaust height 30.

FIG. 2 is a conceptual diagram for explaining the structure of the stripping solution tank 14. The stripper tank 14 has an outer tank 32 and an inner tank 34.
And The outer tank 32 and the inner tank 34 store a resist stripping solution. The resist stripping solution used in the present embodiment is a general amine-based resist stripping solution,
It is composed of multiple components such as water, organic amines, organic solvents, and other additives.

As shown in FIG. 2, the semiconductor wafer 16 is immersed in a resist stripper in an inner bath 34. Inside the inner tank 34, a new liquid supply port 36 and a circulating liquid supply port 38 are provided. The new solution supply port 36 communicates with a new solution tank 40 that stores a new solution of the resist stripping solution at room temperature (room temperature). The new liquid supply port 36 is connected to the new liquid tank 4 as necessary.
The new liquid stored at 0 can be supplied into the inner tank 34. A stripping solution buffer tank 42 communicates with the circulating solution supply port 38. In the stripping solution buffer tank 42, the stripping solution tank 14
A resist stripping solution adjusted to the same temperature as the internal resist stripping solution is stored. The circulating liquid supply port 38 can supply the resist stripping liquid stored in the stripping liquid buffer tank 42 into the inner tank 34 as needed.

The bottom of the inner tank 34 is provided with an openable drain port 43.
Is provided. The drain port 43 has a sufficiently large diameter. Therefore, when the drainage port 43 is used, the inner tank 3
4 can be drained in an extremely short time (hereinafter, such a function is referred to as "Quick").
Dump ").

The upper surface of the inner tank 34 is open inside the outer tank 32. Therefore, the resist stripping solution flows out of the inner tank 34 to the outer tank 32. A conductivity monitor 46 communicates with the outer tank 32 via a circulation path 44. The conductivity monitor 46 is a unit that measures the conductivity of the resist stripping solution supplied from the outer bath 32 through the circulation path 44 and generates a control signal 48 based on the measurement result.

Control signal 48 generated by conductivity monitor 46
Is supplied to the additive component tank 50. The additive component tank 50 stores water and organic amine, which are the main components of the resist stripping solution, respectively, in a single unit.
, Water and organic amine are respectively supplied to the circulation route 52 in appropriate amounts. The additive component (water or organic amine) supplied from the additive component tank 50 is heated in the stripping solution buffer tank 42 together with the resist stripping solution flowing through the conductivity monitor 46 and then supplied into the inner tank 34. You.

Next, the resist peeling device 10 of the present embodiment
The operation of will be described. In the manufacturing process of the semiconductor integrated circuit, the semiconductor wafer 16 is subjected to processing such as dry etching for forming wirings and holes. Immediately after the dry etching, a resist residue adheres to the surface of the semiconductor wafer 16. Such a semiconductor wafer 16, that is, a semiconductor wafer 16 having a resist residue adhered to its surface, is carried into the resist stripping apparatus 10 of the present embodiment. These semiconductor wafers 16 are first transferred by transport arms 18 into stripper bath 14.

A resist stripper heated to a predetermined temperature is stored in the stripper tank 14, and the semiconductor wafer 16 is cleaned by being immersed in the resist stripper. After the cleaning for a predetermined time is performed inside the stripping solution tank 14, the semiconductor wafer 16 is unloaded from the stripping solution tank 14 by the transfer arm 18 and then loaded into the second layer 22. Thereafter, the semiconductor wafer 16 is subjected to rinsing cleaning and water cleaning, and then, through a drying process, to the resist peeling device 10.
It is carried out of the outside. The semiconductor wafer 16 carried out of the resist stripping device 10 is processed by a known method to be a semiconductor device.

The resist stripping liquid stored in the stripping liquid tank 14 is maintained at a predetermined temperature inside the resist stripping device 10 or the chemical liquid is taken out by the semiconductor wafer 16. By being repeatedly performed, the component ratio changes over time. This temporal change in the component ratio is mainly caused by evaporation of water in the resist stripping solution.

In many resist stripping solutions, there is a correlation between the component ratio and the conductivity. Regarding the resist stripping solution used in the present embodiment, a linear relationship as shown in FIG. 3 is recognized between the water content and the conductivity. Therefore, in the present embodiment, the component ratio of the resist stripping solution can be estimated to some extent based on the conductivity.

In the resist stripping apparatus 10 of the present embodiment, the conductivity of the resist stripping solution in the stripping solution tank 14 can be monitored in real time by the conductivity monitor 46. Further, the resist stripping apparatus 10 of the present embodiment has
The relationship between the water content and the electrical conductivity shown in FIG. Therefore, the resist stripping device 10 can estimate the moisture ratio in the resist stripping liquid in real time based on the conductivity of the liquid.

By the way, in the amine-based resist stripping solution used in the present embodiment, strictly speaking, in addition to the water component ratio, the organic amine component ratio also changes relative to the other components. A linear relationship as shown in FIG. 3 is also observed between the ratio of the organic amine and the conductivity. However, since the relationship is not as remarkable as the relationship between the moisture ratio and the conductivity, it is difficult to detect the component ratio of the organic amine based on the change in the conductivity in an environment where the component ratio of the moisture changes significantly. It is.

On the other hand, a certain degree of correlation is recognized between the amount of change in the water ratio and the amount of change in the organic amine ratio generated in the resist stripping solution. Therefore, the ratio of the organic amine is
It can be estimated to some extent by monitoring the change in the moisture ratio. Information necessary for the above estimation is stored in the resist stripping apparatus 10 of the present embodiment in advance. For this reason, the resist stripper 10 can accurately estimate the component ratio (moisture ratio, organic amine ratio, and ratio of other components) of the resist stripper by monitoring the conductivity of the resist stripper. .

The resist stripping device 10 estimates the water ratio and the organic amine ratio by the above-described method, and generates a control signal 48 based on the estimated values. Additive tank 5
0 indicates the amount of water to be added to maintain the water content of the resist stripping solution in the stripping solution tank 14 within the specified range in response to the control signal 48, and the organic amine ratio of the resist stripping solution. The amount of organic amine to be added to maintain the range is supplied to the stripping solution buffer tank 42.

The additive component supplied from the additive component tank 50 flows into the stripping solution buffer tank 42 together with the resist stripping solution flowing through the conductivity monitor 46, and after being heated to an appropriate temperature therein, the circulating solution. Stripper tank 14 from supply port 38
Supplied internally. When the additive component is heated and supplied to the stripping solution tank 14 in this manner, the temperature in the stripping solution tank 14 can be stabilized, that is, the processing conditions for resist stripping can be stabilized.

As shown in FIG. 2, the resist stripping apparatus 10 of the present embodiment performs addition of an additive component upstream of the stripping solution tank 14 and monitoring of conductivity downstream of the stripping solution tank 14. I have. According to such a configuration, it is possible to prevent the influence of the added component from being immediately reflected in the detection result of the conductivity monitor 46. Therefore, according to the resist stripping apparatus 10 of the present embodiment, highly reliable data can be obtained by the conductivity monitor 46.

Hereinafter, the resist stripping apparatus 1 according to the present embodiment will be described.
A procedure for adding an additive component such as water or an organic amine to a resist stripper in circulation is described in more detail. The resist stripper 10 divides factors for changing the component ratio of the resist stripper into the following two factors, and replenishes additional components by a method corresponding to each factor. The first factor is a change that constantly occurs in the resist stripper, including when the resist stripper 10 is in a standby state. The resist stripping apparatus 10 copes with this factor and continuously supplies additional components. Hereinafter, this method is referred to as “continuous supply”.

The second factor is a change accompanying the lot processing of the semiconductor wafer 16, more specifically, a component accompanying the opening / closing of the lid 28 at the time of taking out the chemical solution by the semiconductor wafer 16 and carrying in / out the semiconductor wafer 16. This is a change due to evaporation or the like. The resist stripping device 10 performs intermittent replenishment of the additive component in response to this factor. Hereinafter, this method is referred to as “intermittent supply”.

The resist stripping apparatus 10 of this embodiment performs continuous replenishment by any of the following three methods. (1) The exhaust capacity through the exhaust port 30 is kept constant, and the amount of the additive added is increased or decreased based on the conductivity of the resist stripping solution. (2) The addition amount of the additive component is appropriately increased or decreased based on the electrical conductivity of the resist stripping solution, and the exhaust capability of the exhaust pump 30 is adjusted based on the electrical conductivity. (3) The addition amount of the additive component is fixed to a fixed amount, and the exhaust capability by the exhaust pump 30 is adjusted based on the conductivity of the resist stripping solution.

By adjusting the amount of the added component, the component ratio in the stripping solution tank 14 can be directly adjusted. In addition, since the amount by which the components (mainly water) of the resist stripping solution evaporate per unit time changes according to the exhaust capacity of the resist stripper 10, if the exhaust capacity is adjusted while replenishing the additional components, The component ratio inside the stripping liquid tank 14 can be adjusted indirectly. Therefore, according to the methods (1), (2), and (3), the component ratio of the resist stripping solution can be appropriately controlled in any case. In particular, in the method (2) or (3) using the adjustment of the exhaust capacity, the addition amount of the additional component can be stabilized as compared with the case where the method (1) is used.
Therefore, the methods (2) and (3) are superior to the method (1) in stabilizing the component ratio in the stripping solution tank 14.

In continuous replenishment, only water may be supplied as an additional component, or both water and an organic amine may be supplied. Since the change in the component ratio of the resist stripping solution is mainly caused by the evaporation of water as described above, the change in the component ratio of the resist stripping solution can be suppressed to some extent even if only water is supplied as an additional component. Strictly speaking, organic amines are also lost in trace amounts with the evaporation of water.If an appropriate amount of organic amine is replenished in accordance with the replenishment amount of water, more accurate components can be obtained than in the case where only water is used. In addition, a change in the component ratio can be suppressed.

The resist stripping apparatus 10 of this embodiment performs intermittent replenishment by the following method. As described above, the intermittent replenishment is performed to compensate for the carry-out of the chemical solution by the semiconductor wafer 16. For this reason, in intermittent replenishment, a new resist stripping solution is replenished in principle as an additional component. If the electrical conductivity of the resist stripping solution is greatly deviated from the reference value, water or water and an organic amine are added as additive components in order to bring the component ratio inside the stripping solution tank 14 close to the component ratio of the new solution. Used.

In the present embodiment, the intermittent replenishment of the additional component is performed immediately after the lot of the semiconductor wafer 16 is unloaded from the stripping solution tank 14. When the timing of the intermittent replenishment is set as described above, even if the component ratio in the stripping solution tank 14 changes suddenly due to the intermittent replenishment, the influence can be prevented from affecting the semiconductor wafer 16. Therefore, according to the resist stripping apparatus 10 of the present embodiment, the resist stripping process of the semiconductor wafer 16 can be stably performed while performing the intermittent supply.

Next, measures taken when an abnormality occurs in the conductivity monitor 46 or the mechanism for supplying the additional component will be described. In the resist stripping apparatus 10 according to the present embodiment, if an abnormality occurs in a mechanism for supplying the additional component or the like, there is a possibility that the component ratio in the stripping solution tank 14 may be out of a range suitable for performing the resist stripping process. For this reason, when the conductivity monitored by the conductivity monitor 46 deviates from a preset standard range, and when the conductivity suddenly changes, it is considered that some abnormality has occurred in the device. Once determined, the following measures will be taken.

When the above-mentioned abnormality is detected, new input to the resist stripping device 10 is immediately prohibited for the in-process lot. By taking the above measures, it is possible to prevent a process abnormality caused by a component abnormality of the resist stripping solution.

When the above abnormality is detected, the lot processed in the stripping solution tank 14 is immediately
The immersion in the resist stripper is stopped, and the semiconductor wafer 16
Is immersed in the next tank, that is, the second tank 22. By taking the above-described measures, it is possible to effectively prevent the semiconductor wafer 16 from being unduly eroded.

For the lot in the stripping solution tank 14, the following measures may be taken instead of the above measures. That is, when an abnormality of the resist stripper is detected based on the conductivity, the drainage port 43 of the stripper tank 14 is immediately opened to perform a quick dump of the chemical. Next, after the drain port 43 is closed, a low-temperature resist stripping solution with negligible chemical reaction, more specifically, a new solution at room temperature is supplied from the new solution tank 40 to the stripping solution tank 14. According to such measures, damage to the semiconductor wafer 16 can be minimized, and the safety of the semiconductor wafer 16 at the time of abnormality can be improved.

In the first embodiment described above, the component ratio of the resist stripping solution is estimated based only on the conductivity. However, in order to accurately detect the component ratio, the estimation based on the conductivity is required. And component analysis using an absorbance meter. The estimation based on the electrical conductivity is a technique for indirectly estimating the component ratio of the resist stripping solution, and therefore is excellent in quickly estimating the component ratio, but has a disadvantage that the estimation accuracy is low. On the other hand, the component analysis by the component absorbance meter is a method of directly detecting the component ratio of the resist stripping solution, and therefore has an advantage that a rapid analysis cannot be performed but a highly accurate analysis can be performed. Therefore, by performing both of them in combination, it is possible to realize quick and accurate addition amount control by compensating for the disadvantages of both.

[0061]

Since the present invention is configured as described above, it has the following effects. Claim 1
According to the twelfth aspect, it is possible to replenish the resist stripping solution with the missing component after estimating the component ratio based on the conductivity of the resist stripping solution. Therefore, according to the present invention, the change over time of the resist stripping solution is offset,
The component ratio can be maintained at an appropriate ratio over a long period of time.

According to the invention described in claim 2 or 13,
An appropriate amount of water can be supplied based on the conductivity of the resist stripping solution. The change with time of the resist stripping solution is mainly caused by evaporation of water. Further, the conductivity of the resist stripping solution has a strong correlation with the ratio of water. Therefore, according to the present invention, the component ratio of the resist stripping solution,
It is possible to efficiently and accurately maintain the appropriate ratio.

According to the third or fourteenth aspect of the present invention,
By replenishing the missing components heated to the appropriate temperature to the stripper tank,
It is possible to suppress a temperature change in the stripping liquid tank. Therefore, according to the present invention, the conditions for the resist stripping process can be stabilized.

According to the invention described in claim 4 or 15,
Continuous replenishment can be performed in response to a change that continuously occurs in the resist stripping solution, and intermittent replenishment can be performed in response to an intermittent change that occurs by processing a semiconductor wafer. Therefore, according to the present invention, the component ratio of the resist stripping solution can be efficiently and accurately maintained in an appropriate range.

According to the invention of claim 5 or 16,
The intermittent replenishment of the missing component is performed after the semiconductor wafer is carried out of the stripping solution tank. Therefore, according to the present invention,
Even if the component ratio in the stripping solution tank changes suddenly with the replenishment of the insufficient components, it is possible to reliably prevent the influence from affecting the semiconductor wafer.

According to the invention of claim 6 or 17,
In the circulation path, the replenishment of the missing component is performed downstream of the conductivity monitoring position. Therefore, according to the present invention, after flowing out of the stripping solution tank, the conductivity of the resist stripping solution before the shortage component is replenished, that is, monitoring the conductivity accurately representing the component ratio in the stripping solution tank. Can be.

According to the invention of claim 7 or 18,
By adjusting the ability of the exhaust mechanism for ventilating the atmosphere around the stripping solution tank, it is possible to control how the resist stripping solution changes over time. In other words, according to the present invention, an environment in which components such as water contained in the resist stripping solution disappear at a constant rate can be created by adjusting the exhaust capacity. In this case, the amount of the deficient component to be replenished to the resist stripping solution can be temporally stabilized, and the processing conditions can be stabilized.

According to the invention of claim 8 or 19,
Since the estimation of the component ratio based on the conductivity and the component ratio using the absorbance meter are used together, the component ratio of the resist stripping solution can be detected promptly and accurately.

According to the ninth or twentieth aspect of the present invention,
If an abnormality is found in the component ratio of the resist stripper,
It is possible to prohibit a new semiconductor wafer from being carried into the stripping solution tank. Therefore, according to the present invention, it is possible to prevent a semiconductor wafer from being defective.

According to the tenth or twenty-first aspect of the invention, when an abnormality is found in the component ratio of the resist stripping solution, the semiconductor wafer in the stripping solution tank can be immediately advanced to a subsequent process. Therefore, according to the present invention, it is possible to minimize the loss of the semiconductor wafer due to the abnormality of the resist stripper.

According to the eleventh or twenty-second aspect of the invention, when an abnormality is found in the component ratio of the resist stripping solution, the resist stripping solution in the stripping solution tank can be immediately replaced with a new solution near room temperature. it can. Therefore, according to the present invention, it is possible to minimize the loss of the semiconductor wafer due to the abnormality of the resist stripper.

According to the twenty-third aspect of the present invention, the resist stripping solution used in the process of manufacturing a semiconductor device can be maintained in an economically appropriate state.
A semiconductor device that has stable quality and can be manufactured at low cost can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a resist stripping apparatus according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining a structure of a stripping solution tank provided in the resist stripping apparatus shown in FIG.

FIG. 3 is a diagram showing a relationship between the electrical conductivity of the resist stripping solution and the ratio of water contained in the resist stripping solution.

[Explanation of symbols]

10 resist stripper, 14 stripper bath, 1
6 semiconductor wafer, 18 transfer arm, 30 exhaust port, 32 outer tank, 34 inner tank, 36 new liquid supply port, 38 circulating liquid supply port, 40 new liquid tank,
42 stripper buffer tank, 43 drain port, 4
4, 52 circulation path, 46 conductivity monitor, 48
Control signal, 50 additive tank.

Continuation of the front page (72) Inventor Yoshiyuki Hotori 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 2H096 LA03 5F043 CC16 EE23 EE24 EE28 5F046 MA06 MA10

Claims (24)

[Claims] 1. A resist stripping apparatus for stripping a resist residue adhering to a semiconductor wafer using a resist stripper comprising a multi-component, comprising: a stripper tank for storing the resist stripper; A conductivity monitor for monitoring the conductivity of the stripping solution; a means for estimating a component ratio of the resist stripping solution based on the conductivity; and a lack component of the resist stripping solution based on the estimation result of the component ratio. And a component addition mechanism for adding an appropriate amount to the resist stripping solution. 2. A resist stripping apparatus according to claim 1, wherein said component adding mechanism includes a mechanism for adding water as said insufficient component. 3. The resist stripping apparatus according to claim 1, further comprising a buffer tank for heating the added component, between the component adding mechanism and the stripping liquid tank. 4. A component replenishment mechanism, comprising: a continuous replenishment mechanism for continuously adding the insufficiency component; and a resist stripper for removing the chemical solution from the stripper bath by the semiconductor wafer. The resist stripping apparatus according to any one of claims 1 to 3, further comprising: an intermittent replenishment mechanism that intermittently adds a new solution or the insufficient component. 5. The resist stripping apparatus according to claim 4, wherein the intermittent replenishment mechanism performs the intermittent addition immediately after the semiconductor wafer is unloaded from the stripping solution tank. 6. A circulating path for extracting the resist stripping liquid from the stripping liquid tank and circulating the resist stripping liquid to the stripping liquid tank, wherein the conductivity monitor monitors the resist stripping liquid flowing through the circulating path. The conductivity monitoring unit monitors the conductivity, and the component adding mechanism adds the deficient component to the circulation path downstream from a position where the conductivity monitor monitors the conductivity. The resist stripping apparatus according to any one of claims 1 to 7. 7. An exhaust mechanism for sucking and evacuating an atmosphere around the stripping liquid tank, wherein the exhaust mechanism adjusts an exhaust capacity based on the electric conductivity. The resist stripping device according to any one of the above items. 8. A means for analyzing a component ratio of the resist stripping solution using an absorbance meter, wherein the component addition mechanism uses the component ratio estimated based on the conductivity and the absorbance meter. The resist stripping apparatus according to any one of claims 1 to 7, wherein an insufficient amount of the resist stripping solution is added to the resist stripping solution in an appropriate amount based on both the component ratio to be analyzed. 9. The monitoring data indicating the component ratio of the resist stripping solution indicates that the component ratio is out of a predetermined control range, or the monitoring data indicates a rapid change exceeding a predetermined speed. 9. The resist stripping apparatus according to claim 1, further comprising a unit that prohibits a new semiconductor wafer from being carried into the stripping liquid tank in such a case. 10. 10. The monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined control range, or the monitoring data indicates a rapid change exceeding a predetermined speed. The resist according to any one of claims 1 to 9, further comprising: means for immediately carrying out the semiconductor wafer in the stripping solution tank from the stripping solution tank and transporting the semiconductor wafer to a normal post-process. Stripping device. 11. The monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined control range, or the monitoring data indicates a rapid change exceeding a predetermined speed. In this case, there is provided a means for immediately discharging the resist stripping solution in the stripping solution tank, and further for supplying a new solution of the resist stripping solution near room temperature to the stripping solution tank. 10. The resist peeling device according to any one of items 9 to 9. 12. A method for managing a resist stripping solution composed of multiple components for stripping a resist residue attached to a semiconductor wafer, wherein the conductivity of the resist stripping solution stored in a stripping solution tank is monitored. And estimating the component ratio of the resist stripping solution based on the conductivity; and adding an insufficient amount of the resist stripping solution to the resist stripping solution based on the estimation result of the component ratio. Performing a resist stripping liquid management method. 13. The resist stripping liquid management method according to claim 12, wherein the step of adding the insufficient component includes a step of adding water as the insufficient component. 14. The resist stripping liquid management method according to claim 12, further comprising a step of heating the insufficient component to a predetermined temperature before the insufficient component is supplied to the stripping solution tank. . 15. The step of adding a deficient component includes: a sub-step of continuously adding the deficient component; and a step of removing the resist so as to compensate for a removal of a chemical solution from the stripping solution tank by the semiconductor wafer. 15. A sub-step of intermittently adding a new liquid or the insufficient component.
The resist stripping liquid management method according to the above item. 16. The method according to claim 1, wherein the sub-step of intermittently adding the insufficient component is performed immediately after the semiconductor wafer is unloaded from the stripping solution tank.
5. The method for controlling a resist stripping liquid according to 5. 17. The monitoring of the conductivity is performed on a resist stripping solution flowing out of the stripping solution tank into a circulation path, and the conductivity of the insufficient component is monitored in the circulation path. 17. The resist stripping liquid management method according to claim 12, wherein after being added downstream from the position, the resist stripping liquid flows into the stripping liquid tank together with the resist stripping liquid flowing through the circulation path. 18. The method according to claim 12, further comprising a step of adjusting a capacity of an exhaust mechanism for sucking and exhausting an atmosphere around the stripping liquid tank based on the conductivity. The resist stripping liquid management method according to the above item. 19. The method according to claim 19, further comprising: analyzing a component ratio of the resist stripping solution using an absorbance meter, wherein the step of adding the insufficient component comprises: a component ratio estimated based on the conductivity; 19. The resist stripper according to any one of claims 12 to 18, wherein a deficient component of the resist stripper is added to the resist stripper in an appropriate amount based on both the component ratio analyzed using a meter. Resist stripping liquid management method. 20. Monitoring data representing a component ratio of the resist stripping liquid detects that the component ratio is out of a predetermined management range or that the monitoring data shows a rapid change exceeding a predetermined speed. 20. The method according to claim 12, further comprising: when any one of the two situations is detected, prohibiting a new semiconductor wafer from being carried into the stripping solution tank. The method for managing a resist stripping liquid according to any one of the preceding claims. 21. The monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined management range, or the monitoring data indicates a rapid change exceeding a predetermined speed. Detecting that, when any of the above two situations is detected, the step of immediately carrying out the semiconductor wafer in the stripping solution tank from the stripping solution tank and transporting the semiconductor wafer to a normal post-process, 21. The method according to claim 12, further comprising the step of: 22. The monitoring data indicating the component ratio of the resist stripping liquid indicates that the component ratio is out of a predetermined control range, or the monitoring data indicates a rapid change exceeding a predetermined speed. Detecting that the resist stripping solution in the stripping solution tank is immediately discharged when any of the above two situations is detected, and furthermore, the resist stripping solution near room temperature is added to the stripping solution tank. 21. The method of claim 12, further comprising: supplying a new liquid. 23. A semiconductor device manufactured by using the resist stripping device according to claim 1. Description: 24. A semiconductor device according to claim 12, further comprising the step of removing a resist residue on the semiconductor wafer with a resist stripping liquid managed by the resist stripping liquid management method according to claim 12. Production method.